package us.k5n.journal;

import java.awt.Color;
import java.awt.Component;
import java.awt.Graphics;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Comparator;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Map;

import javax.swing.Icon;
import javax.swing.JLabel;
import javax.swing.JTable;
import javax.swing.event.TableModelEvent;
import javax.swing.event.TableModelListener;
import javax.swing.table.AbstractTableModel;
import javax.swing.table.JTableHeader;
import javax.swing.table.TableCellRenderer;
import javax.swing.table.TableColumnModel;
import javax.swing.table.TableModel;

// Note: this file was found at the following URL:
// http://java.sun.com/docs/books/tutorial/uiswing/components/table.html#sorting

/**
 * TableSorter is a decorator for TableModels; adding sorting functionality to a
 * supplied TableModel. TableSorter does not store or copy the data in its
 * TableModel; instead it maintains a map from the row indexes of the view to
 * the row indexes of the model. As requests are made of the sorter (like
 * getValueAt(row, col)) they are passed to the underlying model after the row
 * numbers have been translated via the internal mapping array. This way, the
 * TableSorter appears to hold another copy of the table with the rows in a
 * different order. <p/> TableSorter registers itself as a listener to the
 * underlying model, just as the JTable itself would. Events recieved from the
 * model are examined, sometimes manipulated (typically widened), and then
 * passed on to the TableSorter's listeners (typically the JTable). If a change
 * to the model has invalidated the order of TableSorter's rows, a note of this
 * is made and the sorter will resort the rows the next time a value is
 * requested. <p/> When the tableHeader property is set, either by using the
 * setTableHeader() method or the two argument constructor, the table header may
 * be used as a complete UI for TableSorter. The default renderer of the
 * tableHeader is decorated with a renderer that indicates the sorting status of
 * each column. In addition, a mouse listener is installed with the following
 * behavior:
 * <ul>
 * <li> Mouse-click: Clears the sorting status of all other columns and advances
 * the sorting status of that column through three values: {NOT_SORTED,
 * ASCENDING, DESCENDING} (then back to NOT_SORTED again).
 * <li> SHIFT-mouse-click: Clears the sorting status of all other columns and
 * cycles the sorting status of the column through the same three values, in the
 * opposite order: {NOT_SORTED, DESCENDING, ASCENDING}.
 * <li> CONTROL-mouse-click and CONTROL-SHIFT-mouse-click: as above except that
 * the changes to the column do not cancel the statuses of columns that are
 * already sorting - giving a way to initiate a compound sort.
 * </ul>
 * <p/> This is a long overdue rewrite of a class of the same name that first
 * appeared in the swing table demos in 1997.
 * 
 * @author Philip Milne
 * @author Brendon McLean
 * @author Dan van Enckevort
 * @author Parwinder Sekhon
 * @version 2.0 02/27/04
 */

public class TableSorter extends AbstractTableModel {
	protected TableModel tableModel;

	public static final int DESCENDING = -1;
	public static final int NOT_SORTED = 0;
	public static final int ASCENDING = 1;

	private static Directive EMPTY_DIRECTIVE = new Directive ( -1, NOT_SORTED );

	public static final Comparator COMPARABLE_COMAPRATOR = new Comparator () {
		public int compare ( Object o1, Object o2 ) {
			return ( (Comparable) o1 ).compareTo ( o2 );
		}
	};
	public static final Comparator LEXICAL_COMPARATOR = new Comparator () {
		public int compare ( Object o1, Object o2 ) {
			return o1.toString ().compareTo ( o2.toString () );
		}
	};

	private Row[] viewToModel;
	private int[] modelToView;

	private JTableHeader tableHeader;
	private MouseListener mouseListener;
	private TableModelListener tableModelListener;
	private Map columnComparators = new HashMap ();
	private List sortingColumns = new ArrayList ();

	public TableSorter() {
		this.mouseListener = new MouseHandler ();
		this.tableModelListener = new TableModelHandler ();
	}

	public TableSorter(TableModel tableModel) {
		this ();
		setTableModel ( tableModel );
	}

	public TableSorter(TableModel tableModel, JTableHeader tableHeader) {
		this ();
		setTableHeader ( tableHeader );
		setTableModel ( tableModel );
	}

	private void clearSortingState () {
		viewToModel = null;
		modelToView = null;
	}

	public TableModel getTableModel () {
		return tableModel;
	}

	public void setTableModel ( TableModel tableModel ) {
		if ( this.tableModel != null ) {
			this.tableModel.removeTableModelListener ( tableModelListener );
		}

		this.tableModel = tableModel;
		if ( this.tableModel != null ) {
			this.tableModel.addTableModelListener ( tableModelListener );
		}

		clearSortingState ();
		fireTableStructureChanged ();
	}

	public JTableHeader getTableHeader () {
		return tableHeader;
	}

	public void setTableHeader ( JTableHeader tableHeader ) {
		if ( this.tableHeader != null ) {
			this.tableHeader.removeMouseListener ( mouseListener );
			TableCellRenderer defaultRenderer = this.tableHeader
			    .getDefaultRenderer ();
			if ( defaultRenderer instanceof SortableHeaderRenderer ) {
				this.tableHeader
				    .setDefaultRenderer ( ( (SortableHeaderRenderer) defaultRenderer ).tableCellRenderer );
			}
		}
		this.tableHeader = tableHeader;
		if ( this.tableHeader != null ) {
			this.tableHeader.addMouseListener ( mouseListener );
			this.tableHeader.setDefaultRenderer ( new SortableHeaderRenderer (
			    this.tableHeader.getDefaultRenderer () ) );
		}
	}

	public boolean isSorting () {
		return sortingColumns.size () != 0;
	}

	private Directive getDirective ( int column ) {
		for ( int i = 0; i < sortingColumns.size (); i++ ) {
			Directive directive = (Directive) sortingColumns.get ( i );
			if ( directive.column == column ) {
				return directive;
			}
		}
		return EMPTY_DIRECTIVE;
	}

	public int getSortingStatus ( int column ) {
		return getDirective ( column ).direction;
	}

	private void sortingStatusChanged () {
		clearSortingState ();
		fireTableDataChanged ();
		if ( tableHeader != null ) {
			tableHeader.repaint ();
		}
	}

	public void setSortingStatus ( int column, int status ) {
		Directive directive = getDirective ( column );
		if ( directive != EMPTY_DIRECTIVE ) {
			sortingColumns.remove ( directive );
		}
		if ( status != NOT_SORTED ) {
			sortingColumns.add ( new Directive ( column, status ) );
		}
		sortingStatusChanged ();
	}

	protected Icon getHeaderRendererIcon ( int column, int size ) {
		Directive directive = getDirective ( column );
		if ( directive == EMPTY_DIRECTIVE ) {
			return null;
		}
		return new Arrow ( directive.direction == DESCENDING, size, sortingColumns
		    .indexOf ( directive ) );
	}

	private void cancelSorting () {
		sortingColumns.clear ();
		sortingStatusChanged ();
	}

	public void setColumnComparator ( Class type, Comparator comparator ) {
		if ( comparator == null ) {
			columnComparators.remove ( type );
		} else {
			columnComparators.put ( type, comparator );
		}
	}

	protected Comparator getComparator ( int column ) {
		Class columnType = tableModel.getColumnClass ( column );
		Comparator comparator = (Comparator) columnComparators.get ( columnType );
		if ( comparator != null ) {
			return comparator;
		}
		if ( Comparable.class.isAssignableFrom ( columnType ) ) {
			return COMPARABLE_COMAPRATOR;
		}
		return LEXICAL_COMPARATOR;
	}

	private Row[] getViewToModel () {
		if ( viewToModel == null ) {
			int tableModelRowCount = tableModel.getRowCount ();
			viewToModel = new Row[tableModelRowCount];
			for ( int row = 0; row < tableModelRowCount; row++ ) {
				viewToModel[row] = new Row ( row );
			}

			if ( isSorting () ) {
				Arrays.sort ( viewToModel );
			}
		}
		return viewToModel;
	}

	public int modelIndex ( int viewIndex ) {
		return getViewToModel ()[viewIndex].modelIndex;
	}

	private int[] getModelToView () {
		if ( modelToView == null ) {
			int n = getViewToModel ().length;
			modelToView = new int[n];
			for ( int i = 0; i < n; i++ ) {
				modelToView[modelIndex ( i )] = i;
			}
		}
		return modelToView;
	}

	// TableModel interface methods

	public int getRowCount () {
		return ( tableModel == null ) ? 0 : tableModel.getRowCount ();
	}

	public int getColumnCount () {
		return ( tableModel == null ) ? 0 : tableModel.getColumnCount ();
	}

	public String getColumnName ( int column ) {
		return tableModel.getColumnName ( column );
	}

	public Class getColumnClass ( int column ) {
		return tableModel.getColumnClass ( column );
	}

	public boolean isCellEditable ( int row, int column ) {
		return tableModel.isCellEditable ( modelIndex ( row ), column );
	}

	public Object getValueAt ( int row, int column ) {
		return tableModel.getValueAt ( modelIndex ( row ), column );
	}

	public void setValueAt ( Object aValue, int row, int column ) {
		tableModel.setValueAt ( aValue, modelIndex ( row ), column );
	}

	// Helper classes

	private class Row implements Comparable {
		private int modelIndex;

		public Row(int index) {
			this.modelIndex = index;
		}

		public int compareTo ( Object o ) {
			int row1 = modelIndex;
			int row2 = ( (Row) o ).modelIndex;

			for ( Iterator it = sortingColumns.iterator (); it.hasNext (); ) {
				Directive directive = (Directive) it.next ();
				int column = directive.column;
				Object o1 = tableModel.getValueAt ( row1, column );
				Object o2 = tableModel.getValueAt ( row2, column );

				int comparison = 0;
				// Define null less than everything, except null.
				if ( o1 == null && o2 == null ) {
					comparison = 0;
				} else if ( o1 == null ) {
					comparison = -1;
				} else if ( o2 == null ) {
					comparison = 1;
				} else {
					comparison = getComparator ( column ).compare ( o1, o2 );
				}
				if ( comparison != 0 ) {
					return directive.direction == DESCENDING ? -comparison : comparison;
				}
			}
			return 0;
		}
	}

	private class TableModelHandler implements TableModelListener {
		public void tableChanged ( TableModelEvent e ) {
			// If we're not sorting by anything, just pass the event along.
			if ( !isSorting () ) {
				clearSortingState ();
				fireTableChanged ( e );
				return;
			}

			// If the table structure has changed, cancel the sorting; the
			// sorting columns may have been either moved or deleted from
			// the model.
			if ( e.getFirstRow () == TableModelEvent.HEADER_ROW ) {
				cancelSorting ();
				fireTableChanged ( e );
				return;
			}

			// We can map a cell event through to the view without widening
			// when the following conditions apply:
			// 
			// a) all the changes are on one row (e.getFirstRow() == e.getLastRow())
			// and,
			// b) all the changes are in one column (column !=
			// TableModelEvent.ALL_COLUMNS) and,
			// c) we are not sorting on that column (getSortingStatus(column) ==
			// NOT_SORTED) and,
			// d) a reverse lookup will not trigger a sort (modelToView != null)
			//
			// Note: INSERT and DELETE events fail this test as they have column ==
			// ALL_COLUMNS.
			// 
			// The last check, for (modelToView != null) is to see if modelToView
			// is already allocated. If we don't do this check; sorting can become
			// a performance bottleneck for applications where cells
			// change rapidly in different parts of the table. If cells
			// change alternately in the sorting column and then outside of
			// it this class can end up re-sorting on alternate cell updates -
			// which can be a performance problem for large tables. The last
			// clause avoids this problem.
			int column = e.getColumn ();
			if ( e.getFirstRow () == e.getLastRow ()
			    && column != TableModelEvent.ALL_COLUMNS
			    && getSortingStatus ( column ) == NOT_SORTED && modelToView != null ) {
				int viewIndex = getModelToView ()[e.getFirstRow ()];
				fireTableChanged ( new TableModelEvent ( TableSorter.this, viewIndex,
				    viewIndex, column, e.getType () ) );
				return;
			}

			// Something has happened to the data that may have invalidated the row
			// order.
			clearSortingState ();
			fireTableDataChanged ();
			return;
		}
	}

	private class MouseHandler extends MouseAdapter {
		public void mouseClicked ( MouseEvent e ) {
			JTableHeader h = (JTableHeader) e.getSource ();
			TableColumnModel columnModel = h.getColumnModel ();
			int viewColumn = columnModel.getColumnIndexAtX ( e.getX () );
			int column = columnModel.getColumn ( viewColumn ).getModelIndex ();
			if ( column != -1 ) {
				int status = getSortingStatus ( column );
				if ( !e.isControlDown () ) {
					cancelSorting ();
				}
				// Cycle the sorting states through {NOT_SORTED, ASCENDING, DESCENDING}
				// or
				// {NOT_SORTED, DESCENDING, ASCENDING} depending on whether shift is
				// pressed.
				status = status + ( e.isShiftDown () ? -1 : 1 );
				status = ( status + 4 ) % 3 - 1; // signed mod, returning {-1, 0, 1}
				setSortingStatus ( column, status );
			}
		}
	}

	private static class Arrow implements Icon {
		private boolean descending;
		private int size;
		private int priority;

		public Arrow(boolean descending, int size, int priority) {
			this.descending = descending;
			this.size = size;
			this.priority = priority;
		}

		public void paintIcon ( Component c, Graphics g, int x, int y ) {
			Color color = c == null ? Color.GRAY : c.getBackground ();
			// In a compound sort, make each succesive triangle 20%
			// smaller than the previous one.
			int dx = (int) ( size / 2 * Math.pow ( 0.8, priority ) );
			int dy = descending ? dx : -dx;
			// Align icon (roughly) with font baseline.
			y = y + 5 * size / 6 + ( descending ? -dy : 0 );
			int shift = descending ? 1 : -1;
			g.translate ( x, y );

			// Right diagonal.
			g.setColor ( color.darker () );
			g.drawLine ( dx / 2, dy, 0, 0 );
			g.drawLine ( dx / 2, dy + shift, 0, shift );

			// Left diagonal.
			g.setColor ( color.brighter () );
			g.drawLine ( dx / 2, dy, dx, 0 );
			g.drawLine ( dx / 2, dy + shift, dx, shift );

			// Horizontal line.
			if ( descending ) {
				g.setColor ( color.darker ().darker () );
			} else {
				g.setColor ( color.brighter ().brighter () );
			}
			g.drawLine ( dx, 0, 0, 0 );

			g.setColor ( color );
			g.translate ( -x, -y );
		}

		public int getIconWidth () {
			return size;
		}

		public int getIconHeight () {
			return size;
		}
	}

	private class SortableHeaderRenderer implements TableCellRenderer {
		private TableCellRenderer tableCellRenderer;

		public SortableHeaderRenderer(TableCellRenderer tableCellRenderer) {
			this.tableCellRenderer = tableCellRenderer;
		}

		public Component getTableCellRendererComponent ( JTable table,
		    Object value, boolean isSelected, boolean hasFocus, int row, int column ) {
			Component c = tableCellRenderer.getTableCellRendererComponent ( table,
			    value, isSelected, hasFocus, row, column );
			if ( c instanceof JLabel ) {
				JLabel l = (JLabel) c;
				l.setHorizontalTextPosition ( JLabel.LEFT );
				int modelColumn = table.convertColumnIndexToModel ( column );
				l.setIcon ( getHeaderRendererIcon ( modelColumn, l.getFont ()
				    .getSize () ) );
			}
			return c;
		}
	}

	private static class Directive {
		private int column;
		private int direction;

		public Directive(int column, int direction) {
			this.column = column;
			this.direction = direction;
		}
	}
}
